Also called as earning income, for which services have been performed or delivered. This includes salaries, commissions, tips, wages and income from businesses in which there is material participation.
Most types of passive income are derived from real estate/property, while other types of passive income are derived from royalties from patents or license agreements.
An income stream falling into this category is one where money is received usually on a regular basis, where no additional effort has taken place. Most passive income streams require great effort to start with.
Some examples: Interest Income paid from bank deposits, rental income from real estate/property, royalties from writing a book, dividends from shares holding.
Another example of passive income come from network marketing.
Passive income flows to you or your family whether you are sick, or vacationing, or dead. Passive income streams allow you to make money without having to be there.
Portfolio income is income from investments, including dividends, interest, royalties, and capital gains. I would say that portfolio income is a subset of passive income.